I am planning to exit these forums, simply because I fear wasting too much time, but I might as well go out with some comments on the E-3, as one of the few FourThirds users here.
In summary, I want it: it is a better choice for my priorities that alternatives like the Nikon D300 (though I am very impressed by its price/performance), Canon 40D, Sony A700, or even the now fire-sale priced Canon 5D.
Increasing resolution has never been a high priority for me, nor action freezing high shutter speeds in low light and the big heavy telephoto lenses that go with the bigger pixels and bigger sensors needed to achieve that. So going beyond 10MP with decent ISO 1600 and usable ISO 3200 would be of very slight value for me: those are the sort of improvements that I would be happy to take, but only if they came at little extra cost and without sacrificing other features of greater value to my photographic interests.
On the other hand, I am greatly attracted by the E-3 offerings of
- in-body stabilization that allows hand-holding in low light even with wide angles (for situations like interior shots with no flash or tripod, but without very fast subject motion to deal with)
[The A700 has this too, but not the D300, 40D or 5D, and Nikon has no stabilized standard zooms, the greatest black mark for me with the D300.]
- Live View for precise manual focusing on a tripod with zoomable live view.
[The D300 and 40D have this too, but not the A700 or 5D. Maybe available soon on a '5DMkII'.]
- 100% viewfinder coverage
[The D300 has this too, but not the 40D, A700, or 5D.]
- A bit more telephoto reach and macro working distance with any given focal length than other SLR systems from the higher absolute sensor resolution (lp/mm) given by its closer pixel spacing. This gives me a somewhat more portable "bird, bug and flower" kit.
I am also happy with the idea of greatly improved AF over the E-1, since AF speed and flexibility has till now been the biggest weakness for Olympus, probably due to its late entry to the AF SLR market. However, this is a relatively minor issue for me, as I do little action photography and the E-1's AF has caused few problems for me.
I will not even pretend to care about frame rate: my operating speed in measured in seconds per frame.